Pivotal mirrors have often been used to reflect light beams from stationary sources to targets of interest. For example, Peisue, "Precision, post-objective, two-axis, galvanometer scanning", SPIE Vol. 390 (1983) describes using galvanometers to quickly and accurately pivot one mirror about one axis and another mirror about another axis to move a laser beam in two axes and direct it to any desired position on a target. Teradyne, Inc.'s prior art M118-M Memory Repair System employs two galvanometers to pivot two mirrors that direct a laser beam to a telecentric lens that is positioned in front of a semiconductor wafer; the beam passes at varying angles to the axis of the lens through the back pupil of the lens (positioned between the two mirrors) and is directed to the target position on the wafer generally parallel to the lens axis.